Incoming flights were suspended at Gatwick airport for almost an hour on Sunday after reports of a drone near the airfield.
Gatwick said 12 incoming flights had to be diverted to other airports because of the alert.
The airport previously cancelled or diverted about 1,000 flights over a three-day period in December 2018 as a result of drone reports. No culprit was found, and there was criticism over the amount of time it took for the runway at the West Sussex airport to reopen.
A Gatwick spokesperson was unable to say whether a drone had been discovered after the latest reported sighting.
They said: “Passenger safety is the airport’s absolute priority and – following established procedures – operations at London Gatwick were suspended temporarily at 13.44 while investigations into the sighting of a suspected drone close to the airfield took place.
“These investigations have now completed and the airfield reopened at 14.35. Twelve inbound aircraft were diverted to other airports during the investigation. However, we expect many of these to return to London Gatwick today.”
British Airways said one of its flights was affected. The plane landed at Stansted before refuelling and returning to Gatwick.
Read more on theguardian.com